Periodic Reporting for period 1 - FLOWCID (Flow Control for Industrial Design)
Berichtszeitraum: 2021-08-01 bis 2023-07-31
Global Postdoctoral Fellowships programme fund the mobility of researchers outside Europe. The fellowship lasts between 2 to 3 years, of which the first 1 to 2 years will be spent in a non-associated Third Country, followed by a mandatory return phase of 1 year to an organisation based in an EU Member State or Horizon Europe Associated Country. Only nationals or long-term residents of the EU Member States or Horizon Europe Associated Countries can apply.
In FLOWCID, the Prof. Eusebio Valero from UNIVERSIDAD POLITECNICA DE MADRID (Spain) has spent 2 years at Purdue University (USA) working with Prof. Guillermo Paniagua in Zucrow Lab in Purdue University (https://engineering.purdue.edu/Zucrow) performing a training and research programme. The main objective of FLOWCID is the development of new methods and tools for the control of flow unsteadiness, in particular the complex non-linear interactions shown in highly detached configurations and unstarting phenomena. To achieve that, we propose the combination of accurate (high order) numerical simulations, flow stability and data analysis techniques, together with detailed experimental studies, aiming to compute and model the flow physics involved in a RDE, then to obtain the sensitivity under perturbations, and finally to define an actuator methodology to control it.
WP1: Application of high order numerical schemes for detached flow prediction. I have been working in improving my High Order Spectral Element solver solver Horses3D (https://numath.dmae.upm.es/tools/horses3d) to include mew capabilitites, in particular by implementing robust turbulent models, h (mesh) o p (polynomial) adaptation for 3D flows with shocks, and appropriate input/output unsteady boundary conditions for turbomachinery applications.
Additionally, these complex computations produce a large amount of data with relevant information. In FLOWCID, these databases are analyzed using mode decomposition methods (https://numath.dmae.upm.es/tools/dinamic-mode-decomposition-dmd/). I have extended these methods to tackle with large turbulent databases, by using data compression techniques and preliminary statistical analysis, which reduce the computational cost. Additionally, those algorithms uncover flow features strongly connected or correlated with some integral value (such as drag or lift), which could be used as a specific target for flow control
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WP2: Analysis of flow sensitivity under external perturbation. I have been working in developing the mathematical machinery needed for sensitivity analysis, in particular algorithms to compute the sensitivity of the eigenmodes (global frequencies) under modifications of base flow, physical o geometrical parameters or external forcing, and by updating previous results considering the effect of different turbulence models in 3D problems. The final aim is to compute the sensitivity of unsteady or even chaotic systems. This information will be incorporated into a gradient-based shape optimization algorithm, which will be used to optimize the target geometry of an internal flow. The experimental verification of those ideas will be performed in Purdue in WP3. Some initial works has been already performed to control a detached shear layer by air injection at some specific location of the trailing edge of a blade.
WP3: Validation and industrial applications and flow control strategies. I will apply the developments of WP1-2 to the analysis and control two canonical configurations of RDE proposed by Prof. Paniagua. Two simplify models of what can happen inside the RDE will be experimentally tested at Purdue. In the framework of pressure induced detachments at high Reynolds numbers, we will investigate 2D and 3D flows around hills at high Reynolds numbers, mimicking the physics of aerodynamic profiles near stall incidence. It is expected the appearance of different solutions, whose stability will give new insight into the sudden change in topology from an attached high-lift steady flow to a detached low-lift unsteady flow. The control of stall phenomenon will be investigated by using the information provided by the sensitivity analysis
FLOWCID aims to consolidate a leading and reference European/American research team in simulation and flow control that can be applied to turbo machinery or aircraft industry, in the design of the new generation of engines and aircraft propelled by hydrogen, with outstanding benefits and impacts of environment and fuel consumption.
Additionally, FLOWCID is consolidating the position of Prof. Valero as an international reference in simulation, sensibility and control and it is promoting the transfer of knowledge between America and Europe by the exchange of junior and senior researchers, promoting their mobility and having a positive impact on their respective career prospect.